1. Field of the Invention
The present disclosure relates to a charger that charges a high-voltage battery and a low-voltage battery, the high-voltage battery providing a 3-phase motor equipped in an electric vehicle with a driving power, the low-voltage battery providing electronic elements and a lamp device equipped in the electric vehicle with an operating power. More particularly, the present disclosure relates to a charger that charges the high-voltage battery, charges the low-voltage battery using the power charged in the high-voltage battery while controlling a power factor of an input commercial AC (alternating Current) power at about 1 by operating a buck-type single-phase rectifier, a 3-phase motor and an inverter in a buck-boost operation, and can combine control and communication using one DSP (Digital Signal Processor) with an advantage of wiring by combining an inverter, a high-voltage charger and a low-voltage charger.
2. Description of the Related Art
Generally, an electric vehicle includes a high-voltage battery in which a high-voltage of about 72V is charged, for example, a 3-phase motor which is driven by power charged in the high-voltage battery and drives the vehicle, and an inverter which drives the 3-phase motor.
However, the method has a limit to drive the 3-pahse motor with the charged power of the high-voltage battery, that is, it is not possible to drive the 3-phase motor any more when the power charged in the high-voltage battery is discharged more than a predetermined power level.
To obviate some or all of the prior art disadvantage, the electric vehicle includes a high-voltage charger that charges the high-voltage battery with its output power.
Further, the electric vehicle includes electronic units, lamp devices and different kinds of loads using a low-voltage power such as 12V power, as well as the 3-pahse motor, which has a low-voltage battery to operate loads which use the low-voltage power and a low-voltage charger to charge the low-voltage battery with a low-voltage power.
However, since the inverter, high-voltage charger and low-voltage charger are included separately with one another, it takes much time and labor to design an electric vehicle having each of the inverter, high-voltage charger and low-voltage charger mounted thereon.